Visual stimuli may be evaluated using viewing data regarding the stimuli to evaluate the effect on the stimuli on a viewer. Viewing data may be collected using devices such as eyetracking devices, which operate to track the movement of a person's face and eyes as that person engages in an activity. In particular, eyetracking devices may record viewing data in connection with the use of a computer system. Eyetracking devices may consist of a camera and associated electronic components to produce data representing gaze positions. This data can be used to determine where the individual is looking, which can be described in terms of fixations (a steady gaze for a predetermined period of time) and saccades (movement of the gaze between two points).
Eyetracker data may be combined with data representing graphical or visual images presented to a user to generate viewing data indicating what a person was viewing. The viewing data can be used, for example, to determine whether a viewer has looked at all of the information presented, or whether a person made certain choices in connection with the information presented. The viewing data may be presented in a report, which may include graphical representations of the data.
Viewing data may be collected for the purpose of studying particular presentations, web sites, advertising, or other visual stimuli, and studies are generally conducted for certain intended users of the data. However, in conventional operations the recording and processing of viewing data are closely connected, such as in the operation of single machine. The interconnection of recording and processing of data means that the collector of data also has access to analysis, and to the purposes of the data collection, which creates implications for data security and other issues. The collection of viewing data may include the processing provided in U.S. Pat. No. 6,712,468, regarding a “heat map” that is generated from collected data.
However, conventional operations assume that any analysis generated with regard to a given visual stimulus was generated from data collected using that exact same stimulus to which the analysis is associated. In general it is necessary to gather eye-tracking data for every new presentation of stimuli in order to estimate how changes in the stimuli may affect a viewer. For example, if a computer web page or other visual representation is modified, a new test of the effectiveness of the presentation may be needed for each version of the presentation.